[sci.military] Strange Looking Weapon

wilkinson@PICA.ARMY.MIL (CCL-C) (03/15/91)

From:     Peter Wilkinson (CCL-C) <wilkinson@PICA.ARMY.MIL>
>  Scott Silvey asks about the strange looking weapon on top of the
>  FAV in Newsweek.

Well, Bill, you're right once again.
The weapon is the MK 19 Mod 3, 40mm, GMG (Grenade Machine Gun). It is
belt fed (48 rd box), air cooled, blowback (advanced primer ignition)
operated and fires from an open bolt.  < For an explanation, ad
nauseum, of the differences between blowback, recoil, and gas
operation of machine guns I would refer the reader to Vol. IV of "The
Machine Gun", compiled by George M. Chinn, Col., USMC (Ret.), Edwards
Bros., Ann Arbor, MI.>

Stats on MK 19 are:  Wt. 75.6 lbs (gun)
                         22 lbs   (cradle)
                         44 lbs   (tripod)
                     Len. 43.1 in.
                     Wid. 13.4 in.
                     Ht.   8.8 in.
                     Cyclic RoF  350 +/- 25 rpm
                     Range: Max  2200 m
                            Effective 1500 m (point targets)
                                      2200 m (area targets)
                     Mounted on: M998T, M1025-1026 HMMWV's
                                 M113 APC
                                 M88 RV
                                 M3 Tripod
                                 LVTP7A1 (50-40 upgunned turret)
                     Ammunition: Std A Combat Rd  M430 HEDP
                                 Std B  "         M383 HE
                                 Trng Rds         M918 TP (flashbang)
                                                  M385 TP (inert)
                                 Muzzle Vel  790 fps

The M430 HEDP incorporates a shaped charge and will defeat at least 2
in. of RHA, while inflicting fragmentation casualties outside the
vehicle (5 m lethal rad).
The effective range to point targets is governed by the ability to
achieve a hit. Given a hit, a shaped charge is effective at any
range.
The weapon is principally used against exposed personnel, lightly
armored (BMP, BTR, BRDM), and thin skinned (trucks) vehicles.
The weights given above betray the gun's naval origins. In the mid-
sixties, Naval Ordnance Station, Louisville designed the MK 19 Mod 0
in response to the need for more firepower on riverine patrol craft
in RVN. In 1969, NOSL undertook to remedy certain reliability and
safety problems, resulting in the MK 19 Mod 1. Approx. 600 of this
model were sold/given to the IDF, but, more importantly, about 200
were lost to the present regime in Viet Nam. It is widely believed
that Soviet advisors were so impressed by being on the receiving end
of a grenade machine gun attack that this led them to reverse
engineer the Mod 1, resulting in their 1977 fielding of the 30mm AGS-
17.
An attempt by bureaucrats to improve the Mod 1 resulted in the Mod 2,
which was perfect in every way, except that it wouldn't shoot.
In 1980, the USMC identified a deficiency in their ability to deal
with light armor, and so a requirement for a HMG with good anti-armor
capabilities was drafted. Although called a PIP (product improvement
program) of the Mod 1, the resulting Mod 3 was, in fact, a complete
redesign. The barrel was lengthened, the receiver material was
changed from AL to steel, and many other changes were incorporated
which greatly improved the RAM and safety aspects of the weapon.
Guns built in-house by NOSL were first fielded to USAF units in
Europe in 1985 for GLCM base security purposes. In 1986 Saco Defense,
Inc, Saco, Me began deliveries of guns to USMC. In Nov 1989, the 9th
ID became FUE (first unit equipped) in the Army, although prior to
this, they did have Mod 1's (as well as Fast Attack Vehicles) for
training and evaluation. Guns were fielded to 7th ID in June 1990.
For reasons which should be obvious, in Sept. 1990 most of the 9th
ID's guns were hurriedly turned over to the 24th ID.  This weapon
represents (IMHO) a considerable asset to infantry, either mech. or
dismounted in a defensive posture. Thanks to firing from an open
bolt, the low chamber pressures (13-15 kpsi), and the relatively
small amount of propellant (approx. 4 gm), cookoff is not a problem.
The Mod 3 will keep shooting as long as you can keep feeding it. In
one test, under operational conditions, 5 guns fired over 7,000 rds
with 3 stoppages, all clearable in less than 20 sec.  A selector
switch is not needed, as the cyclic rate is low enough to allow a
novice to squeeze off singles all day long (I've done it).  It's
versatility becomes apparant when you realize that it can be mounted
anywhere the venerable M2 can. And at $12,000 a copy, with ammo at
$12.00 a round, it's rather cost effective, as BMP killers go.


                                          Pete Wilkinson
                                          (One Shot)